Rapid, simple techniques for MHC class II typing were explored to facilitate the use of a wide variety of nonhuman primate species as models of human diseases and therapies. We demonstrate that radioimmunoprecipitation and 1-D IEF or 1-D NEPHGE can be employed for characterizing MHC class II DR alleles in rhesus monkeys. Complementary molecular analyses have yielded the first full-length nonhuman primate DRA sequence and the first full-length rhesus macaque DRB sequences. In this way it has also been possible to determine which subset of the DRB sequences amplified from a B-LCL are actually expressed.